294 research outputs found
ParFORM: recent development
We report on the status of our project of parallelization of the symbolic
manipulation program FORM. We have now parallel versions of FORM running on
Cluster- or SMP-architectures. These versions can be used to run arbitrary FORM
programs in parallel.Comment: 5 pages, 6 Encapsulated postscript figures, LaTeX2e, uses espcrc2.sty
(included). Talk given at ACAT0
Cloning and sequencing the urocanase gene (hutU) from Pseudomonas putida
AbstractA clone harbouring the entire urocanase gene (hutU) was obtained from a genomic library of Pseudomonas putida using oligonucleotide probes synthesised on the basis of known flanking sequences. One subunit of urocanase consists of 556 amino acids and has a molecular mass of 60 771 Da
Limits on Lorentz Violation from the Highest Energy Cosmic Rays
We place several new limits on Lorentz violating effects, which can modify
particles' dispersion relations, by considering the highest energy cosmic rays
observed. Since these are hadrons, this involves considering the partonic
content of such cosmic rays. We get a number of bounds on differences in
maximum propagation speeds, which are typically bounded at the 10^{-21} level,
and on momentum dependent dispersion corrections of the form v = 1 +-
p^2/Lambda^2, which typically bound Lambda > 10^{21} GeV, well above the Planck
scale. For (CPT violating) dispersion correction of the form v = 1 + p/Lambda,
the bounds are up to 15 orders of magnitude beyond the Planck scale.Comment: 24 pages, no figures. Added references, very slight changes. Version
published in Physical Review
Order perturbative QCD corrections to the Gottfried sum rule
The order perturbative QCD correction to the Gottfried sum rule
is obtained. The result is based on numerical calculation of the order
contribution to the coefficient function and on the new estimate
of the three-loop anomalous dimension term. The correction found is negative
and rather small. Therefore it does not affect the necessity to introduce
flavour-asymmetry between and antiquarks for the
description of NMC result for the Gottfried sum rule.Comment: LaTeX, 7 pages, the discussions of the corrections to
the anomalous dimension are modified; 1 reference added; to be published in
Phys. Lett.
Higgs Boson Production at Hadron Colliders
I report on a calculation of the inclusive Higgs boson production cross
section at hadron colliders at next-to-next-to-leading order in QCD. The result
is computed as an expansion about the threshold region. By continuing the
expansion to very high order, we map the result onto basis functions and obtain
the result in closed analytic form.Comment: 3 pages, 2 figures, uses espcrc2.sty. Talk presented at XXXIst
International Conference on High Energy Physics, Amsterdam, The Netherlands,
24-31 July, 200
alpha_s^3 conversion relation betweeen MS-bar and Euclidean quark masses
We report on the analytical calculation of NNNLO (of order alpha_s^3)
conversion factor between the MS-bar quark mass and the one defined in the
so-called Regularization Invariant scheme. The NNNLO contribution in the
conversion factor turns out to be relatively large and comparable to the known
NNLO term.Comment: 4 pages, Latex, uses espcrc2.sty. The paper is also available via
anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ttp99/ttp99-39/ or via
www at http://www-ttp.physik.uni-karlsruhe.de/Preprints
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